Problem: A goblet contains $11$ red balls, $8$ green balls, and $5$ blue balls. If a ball is randomly chosen, what is the probability that it is not red?
Answer: There are $11 + 8 + 5 = 24$ balls in the goblet. There are $11$ red balls. That means $24 - 11 = 13$ are not red. The probability is $ \frac{13}{24}$.